For a ketone at equilibrium in a given solvent, the tautomerisation constant is $K_{T} = [enol] / [keto] = 0.37$ . Calculate the percent enol content at equilibrium, to one decimal place.

Numerical answer type, answer in %, tolerance 0.05.

Answer: 27 %

Percent enol

= 100 K_{T} / (1 + K_{T})

. With

K_{T} = 0.37

, this is

100 \times 0.37/1.37 = 27.0

. The result is

27.0%